Cargo pants can be exploited for extra inventory space.

Taking only four (2x2) slots in the inventory, they can contain up to six items and still be stored on 2x2 slots.
It is even possible to put on one pair of cargo pants, put one containing 6 items into it and fill up the remaining 2 slots with whatever. then drop the pants containing the container pants on the ground, put on a third pair of cargo pants and drop the first into it.
Tataa: a total of 10 ((6+2)+2) item slots accomplished in your pants only. :D